Exercise has a long list of health benefits, and a study published in PLOS One suggests there might be another, rather intriguing one: a greater tolerance for pain.
The study, which followed more than 10,000 adults for eight years, found that those who regularly exercised had a higher pain tolerance than those who were consistently sedentary. And if they remained physically active over time, they retained that pain-tolerance advantage.
Pain tolerance refers to the degree of pain you feel you can reasonably handle. It’s well known that individuals vary in their pain tolerance—a fact that helps explain why, for example, a muscle strain is uncomfortable for one person and excruciating for another.
Many factors may influence pain tolerance, but the findings suggest that exercise habits might be one. “This study implies that every additional bit of activity might help improve your pain tolerance, which has been suggested to protect against chronic pain,” said lead researcher Anders Arnes, PhD, of University Hospital of North Norway.
If so, that would be good news, since we have limited safe and effective ways to manage chronic pain. If physical activity can help blunt people’s sensitivity to pain signals from conditions like arthritis, fibromyalgia, or migraines, that would be a valuable non-drug option. Plus, regular exercise is already recommended for a host of health reasons.
A smart(ing) study
The findings are based on 10,732 Norwegian adults, average age 56 at the start, who answered surveys on their lifestyle habits in 2007–2008 and then again eight years later. The participants also took a standard pain-tolerance test used in research: It asks people to submerge their hand in icy water for as long as they can handle—for up to two minutes.
On average, the researchers found, the more physically active people were, the longer they could endure the cold water. Those who reported moderate to vigorous exercise levels in both surveys were the most stoic—averaging 20 seconds longer in the chilly conditions, versus people who were sedentary at both time points.
Of course, there’s the chicken-and-egg question. It could be that people with greater pain tolerance find it easier to exercise. The study found hints that might not be the full explanation, however. Participants who became newly active or increased their exercise levels after the first survey seemed to gain from it: They performed better on the second pain-tolerance test, compared to consistently inactive folks.
Still, it’s important to stress that this type of study cannot prove cause-and-effect. The researchers did not test the direct effects of physical activity on pain tolerance but rather based their conclusions on self-reports of exercise assessed at two periods of time. And they didn’t look at whether exercise can prevent or treat any chronic pain condition.
That said, Arnes pointed to past research, in both humans and lab animals, that has put exercise to the test. In general, the findings suggest that physical activity can help change pain sensitivity, in both healthy people and those with chronic pain.
Why might physical activity have this effect?
Based on past research, it could well involve both physiological and psychological factors, according to Arnes. On that first front, physical activity does seem to activate the body’s natural pain-reducing capacity: A familiar example would be the “runner’s high” attributed to an acute release of endorphins—chemicals that are part of the body’s own opioid system.
“Exercise can be experienced as uncomfortable—or downright painful—but that sensation occurs within a positive, voluntary context and triggers a whole lot of pain-inhibiting processes in the nervous system,” Arnes said.
That experience, repeated regularly, might also have pain-easing benefits that go beyond an endorphin rush. According to Arnes, it may help us “reframe other experiences of pain we might have, and also increases our belief that the experience is something we can manage.”
BOTTOM LINE: Regular exercise is a vital component of wellness—and often recommended by pain specialists and some other healthcare providers to help manage chronic pain. These latest findings provide yet more reason to get (or keep) moving if you are living with chronic pain. Plus, Arnes noted, you don’t have to run a marathon: Think moderate activities (that daily brisk walk) that you can maintain. “The most important thing is that you do something, and preferably something enjoyable.”
